Pharmaceutical tablets are traditionally given a finishing film coating that is designed to provide a gloss or shine to the final tablet in order to improve the appearance to the consumer. A commonly practiced method is to apply a thin layer of unpigmented coating on top of the usually pigmented color coat. While this method is generally successful when the final coating is applied with an organic solvent, there have been problems using aqueous based coatings. The result is often a low shine or dull appearance in contrast to tablets prepared with an organic solvent method.
FMC Corporation has produced a looseleaf manual on film coating entitled AQUACOAT The Revolutionary Aqueous Coating System available from FMC Corporation, Food and Pharmaceutical Products Division, 2000 Market Street, Philadelphia, Pa. 19103, which provides information on the use of a 24 inch Accela-Cota.RTM. pan for color coating and gloss coating of several vitamin products Machine settings and formulations are given therein. The formulations and process described in this manual are typical for gloss coating, or shining, of pharmaceutical tablets when using aqueous based film coating solutions. The process described is a continuous coating process, i.e. a gloss coating solution is applied at a continuous rate. That rate is chosen to be consonant with the capability to continuously dry the tablet surfaces of the newly applied gloss coating solution. The gloss coating solution formulation provided is also typical and is based on the use of unpigmented hydroxypropyl methylcellulose, (HPMC), plasticized by liquid plasticizers, in an effort to achieve film clarity and flexibility.
Tablets coated by the method of this invention have an improved appearance over those made with the settings and formulations suggested in the FMC manual.
Vitamins coated by the method of this invention were shipped in interstate commerce Nov. 7, 1988, by MILES INC., 1127 Myrtle Street, Elkhart, Ind. 46514, under the trademark One-A-Day.RTM. Maximum Formula.
This invention provides a method to produce a shine coating with aqueous coating solutions or with water; thereby avoiding both the problem of exposure of workers to organic solvents and the problem of disposal of the organic solvents.